The present invention relates to a medical apparatus and method for joint immobilization, and, in particular, to a method and apparatus for immobilizing the thumb CMC joint to eliminate pain.
The thumb trapeziometacarpal joint, also call the thumb carpometacarpal joint (CMC joint), is the most common site in the upper extremity of the human body for surgery due to disabling osteoarthritis, which is particularly prevalent in postmenopausal women, many of whom already have laxity of the joint. Osteoarthritis causes increased laxity of the thumb CMC joint capsule, creating a common clinical complaint of pain upon resistive thumb motion, such as experienced during forceful pinching.
Immobilization splinting is used by most surgeons and therapists as part of a conservative, non-surgical treatment for painful thumb CMC joints. Typical immobilization splint involve one and often both adjacent joints. Such comprehensive immobilization results in poor patient compliance and limitation of hand function, both of which appear to be related to the number of immobilized joints. Immobilization of the thumb MP joint limits flexion. Extension and abduction/adduction. Immobilization of the wrist demands greater range of proximal joint, making function more demanding. Accordingly, the patient must choose the benefits of compliance against the loss of functional use through immobilization.
It would therefore be a significant advance in the art, and is accordingly an object of the present invention, to reduce the number of joints adjacent the thumb CMC joint that must be immobilized, in addition to the thumb CMC joint, to reduce pain and increase compliance. A further object of the present invention is to reduce the size of the splint for immobilizing the thumb CMC joint for affording greater comfort for the patient lessening interference with functionality thereby increasing patient compliance.
The foregoing objects are accomplished by a novel thumb CMC joint splint for reducing joint pain without loss of hand functionality thereby increasing patient compliance. In certain prior splint designs, rigid custom molded thermoplastic splints have been employed immobilizing the joint and wrist. Other designs have employed non-rigid materials, such as leather or fabric, that encompass the thumb and wrist joints to provide global support therefor. In a preferred embodiment of the present invention, the splint comprises an adjustable wrist band, formed of a soft good such as neoprene laminated with a cloth knit, having a dorsal flap that overlies the side and bottom of the CMC capsule. An elongated tensioning strap is attached at one end to the top surface of the wrist band and is tensioned over the dorsal flap and attached thereto at a first attachment location to provide peripheral support at the capsule. The tensioning strap extends forwardly around the capsule and extends rearwardly over the web between the thumb and the first finger with the distal end tensioned and releasably connect to the wrist band at a second attachment location thereby outwardly spacing the thumb and immobilizing the CMC joint, without loss of thumb or adjacent joint functionality.